DE-OS No. 2 335 204 discloses a weft yarn store whose function is merely to prepare a sufficient supply of yarn for picking but not to size the yarn according to cloth width. A store of such a kind would be unsuitable, for instance, for use in air jet looms since the weft yarn must have a definite length during picking to obviate any substantial excess of yarn on the catching side of the loom after picking.
Other proposals for loom weft yarn stores have sought to deal with the matter of pick length, but the structures proposed have left room for improvement. High speed loom operations impose unusual demands on modern yarn handling systems.